A study of the risk of end stage renal disease (ESRD) among silica (14808607) exposed gold miners was conducted. The cohort consisted of 2,412 white males who were employed at a South Dakota gold mine for at least 1 year between 1940 and 1965 and were alive on January 1, 1977. The cohort had been constructed by NIOSH for a previous mortality study and was followed to the end of 1992. The incidence of ESRD in the cohort was determined by linking the subjects to the ESRD Program Management and Medical Information System (PMMIS). The ESRD PMMIS was a database that contained information on every individual with ESRD who received Medicare covered renal replacement, dialysis, or transplant therapy in 1977. Standardized incidence ratios (SIRs) for ESRD in the miners were computed using ESRD incidence rates in the US population as the reference. ESRD SIRs were also examined according to duration of underground employment and cumulative silica dust exposure. The mean duration of employment of the cohort underground was 8.0 years. The miners experienced cumulative silica dust exposures of 0.008 to 4.32 milligram years per cubic meter (mg-yr/m3), mean 0.39mg-yr/m3. The median intensity of silica exposure was 0.05mg/m3, below the OSHA standard of 0.09mg/m3. Eleven miners, seven of whom died before December 31, 1992, were identified as being treated for ESRD. These cases represented an overall ESRD SIR of 1.37. The greatest risk was for glomerulonephrosis or interstitial nephritis (nonsystemic nephritis), SIR = 4.22. The SIR increased to 7.70 for miners with 10 or more years of underground employment. Four cases of nonsystemic ESRD occurred among miners with 0.22 to 0.54mg-yr/m3 cumulative silica exposure, yielding an SIR of 11.05. Only one case of nonsystemic ESRD occurred among miners with the greatest cumulative silica exposure, 55mg-yr/m3. The authors conclude that this study provides evidence that occupational exposure to silica dust is associated with an increased risk for ESRD. Although the small number of cases does not enable a definitive conclusion to be drawn, the current OSHA standard does not appear to protect against the nephrotoxic effects of silica.